On 23.10.19 г. 15:56 ч., Qu Wenruo wrote:
> The old code goes:
>
> offset = logical - em->start;
> length = min_t(u64, em->len - offset, length);
>
> Where @length calculate is dependent on offset, it can take reader
> several more seconds to find it's just the same code as:
>
> offset = logical - em->start;
> length = min_t(u64, em->start + em->len - logical, length);
>
> Use above code to make the length calculate independent from other
> variable, thus slightly increase the readability.
>
> Signed-off-by: Qu Wenruo <[email protected]>
I agree, this calculates whether we need to trim the rest of the BG or
not.
Reviewed-by: Nikolay Borisov <[email protected]>
> ---
> fs/btrfs/volumes.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index cdd7af424033..a6db11e821a5 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -5616,7 +5616,7 @@ static int __btrfs_map_block_for_discard(struct
> btrfs_fs_info *fs_info,
> }
>
> offset = logical - em->start;
> - length = min_t(u64, em->len - offset, length);
> + length = min_t(u64, em->start + em->len - logical, length);
>
> stripe_len = map->stripe_len;
> /*
>
